Roulette is a gambling game in which a croupier spins a wheel in one direction then rolls a ball in the opposite direction on a tilted rim surrounding the wheel. The ball eventually falls into one of many colored and numbered pockets on the wheel. Players place bets on various aspects of the result, such as the winning number, the color of the pocket, whether the number is odd or even, etc. The pockets are numbered from 1 to 36, alternating between red and black. There is a green pocket numbered 0. In American roulette, there is a second green pocket marked 00. Pockets are not in numerical order around the wheel. Some consecutive numbers are the same color.
Players can make a variety of “inside” bets by selecting the number of the pocket the ball will land in or a range of pockets based on their position, and/or players can make “outside” bets on various positional groupings of pockets, pocket colors, or odd or even pocket numbers. The payout odds for each type of bet are based on its probability of success. The table usually imposes minimum and maximum bets, and these limits usually apply separately for all of a given player's inside and outside bets for each spin. Players can continue to place bets until the dealer announces “No more bets.” Betting areas on a roulette table are covered with cloth having a tabular arrangement known as a layout.
Inside Bets
Straight: a bet on a single pocket number.
Split: a bet on two adjoining numbers on the layout.
Street: a bet on three numbers on a single horizontal line on the layout.
Corner: a bet on four numbers in a square arrangement on the layout.
Line: a bet on two adjoining streets on the layout.
In a typical roulette game, odds are paid out by the casinos on inside bets as follows:
                a straight bet pays 35 to 1. A single chip wining on a straight pays 35 chips.        a line bet pays 5 to 1;        a street bet pays 11 to 1;        a corner bet pays 8 to 1;        a split bet pays 17 to 1;        
Players can make different types of bets on the same game. After the wining number is determined, the croupier must then determine the payout to each winning player. The mathematical calculations of multiplying and adding to determine combined payouts can be cumbersome and error-prone.